Internal combustion engines of usual design employ mechanical crankshafts to convert piston reciprocation to rotational motion for the drive shaft. Such mechanically linked engine systems have inherent a number of performance and carburetion drawbacks which result in operational inefficiency, high construction and high maintenance and operation costs.
One such drawback is the criticality of ignition timing and, related thereto, minimum fuel octane requirements. As a result of direct and inflexible mechanical crankshaft linkages, faulty timing or the use of fuel of insufficient octane rating can result in destructive preignition or knocking. Another result is the requirement for complicated and expensive gear mechanisms for automatic transmissions.
Still another drawback is limitation of the types of carburetion systems which can be used. Exhaust pollutants such as oxides of nitrogen could be eliminated or substantially reduced if oxygen, or a blend of oxygen and air, were usable as a fuel component rather than air (of which 78% is nitrogen). However, use of oxygen in a standard internal combustion engine would present inordinate detoration-preignition, vibration problems and danger of oxygen concentration in the crankcase chamber making the motor unsafe. Indeed, a "spongy" power thrust is necessary for standard engines, and made possible by nitrogen dilution. Other disadvantages stem from the fact that the combination of carburetion and crankshaft mechanism requires a compression stroke so that the engine draws in fuel and fires even when power is not being applied to the drive shaft. As one result, the engine uses fuel at all speeds, even when coasting, and when idling. At high speeds, e.g. 50 mph and higher, excessive vacuum developed by the engine sucks in considerable fuel even when the engine is not being throttled. As another result, an expensive, battery-consuming starting motor is needed to provide initial compression.
The present invention provides a piston engine with motion conversion and carburetion features that eliminate the foregoing drawbacks. The engine employs a flywheel rotor, in lieu of a crankshaft, driven hydraulically by the piston with no direct coupling to the piston. Combustion or starting of the motor is obtained by spark-ignition of injected fossil type fuel, preferably along with oxygen or oxygen-air blend, controlled by a variable D.C. motor.
Specifically, one end of a plunger is connected to the piston, the other end being slidably disposed in an hydraulic cylinder. During a combustion stroke, the piston-driven plunger displaces hydraulic fluid in the cylinder through a high speed orifice to impinge against spaced cavity surfaces formed along the periphery of the rotor, thereby spinning the rotor. A slide valve is disposed at the head of the high speed orifice and is hydraulically connected to the cylinder. By such means, pressure changes in the cylinder reciprocate the slide valve to provide momentary delay, during pressure build-up, and then release of the cylinder fluid, thereby increasing the fluid velocity and imparting greater kinetic energy. Hydraulic fluid is recirculated during an exhaust stroke wherein the piston is returned by injected air pressure. Air used to return the piston acts as a coolant and also flushes to exhaust any stray oxygen that might accumulate below the piston.
A fuel injection system is used and ignition is timed so as to fire when the piston reaches top dead center. However, timing is not critical nor is octane rating of the fuel; gasoline, diesel fuel or jet fuel can be used by slight adjustments. Since the piston is not coupled directly to the flywheel rotor, the only affect of preignition is to lose power. There is no post-ignition. As a result of using lower air pressure forces only to return the piston to a combustion mode, very low octane fuels can be used. Since slippage of the flywheel is possible at low speeds, only a gear box with forward, backward and lock positions is required. Thus, complex automatic transmission mechanisms can be eliminated.
The absence of pre-ignition problems also makes possible the use of oxygen to replace part or all of the air, enabling the elimination or substantial reduction of oxides of nitrogen and enabling a greater conversion of carbon monoxide to carbon dioxide. Furthermore, closer control over fuel usage and combustion is possible, decreasing the amount of unburned hydrocarbons in the exhaust. Fuel efficiency by use of low cost oxygen or oxygen-air blend, readily available, is greater than with the present inefficient internal combustion type motors.
By using an ignition system coupled to a D.C. motor-driven fuel supply, power is applied, independently of drive shaft rotation, by operation of a rheostat (which can be connected to a conventional foot pedal). Accordingly, fuel is applied only under driver control, irrespective of the speed of the vehicle enabling substantial fuel economy. Since the engine need not be "turned over" to operate, a starting motor is not needed.
Still another advantage of the present engine is the ability to produce additional braking power at high speeds, as will be described hereinafter. Other advantages and features of the invention will be apparent from the following description.